Aldehyde odor (arudehito-shu)
アルデヒト臭あるでひとしゅうAldehyde odor (arudehito-shu) is an aroma that arises mainly during sake production, particularly when fermentation of the moromi (fermentation mash) is active. It is caused by acetaldehyde and is often noticed after pressing (joso). Aldehyde odor is characterized by a fragrance resembling wood, and this similar scent is sometimes called a "wood-like odor" (mokkoyo-shu). When the aroma is strong, it can affect the quality of the sake, so care is needed.